Turbine.



No. 858,206. PATEN-TED JUNE 25. 1907 G. A. PARSONS. TURBINE.

' APPLICATION FILED AUG.6, 190s.

2 SHEETSSHEET 2 Fig. 5

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STA'EEb PATENT TURBQNER Specification of Letters Patent.

Patented June 215,

Application filed August 5, 1906- Serial No- 329,444.

To all whom it may concern.-

Newcastle-upon-Tyne, in the county of Northumberland, England, have invented certain new and useful Improvements in Turbines, of which the following is a specification.

This invention relates to steam and like turbines in which the energy of the working fluid is abstracted in a number of stages and is specially directed toward the shaping and arrangement of the blades toward the outlet end of the turbine. In turbines of this class considerable diificulty arises in de aling with the large volume of expanded fluid toward the outlet end or in the lower pres sure parts because with the ordinary methods of blading it is necessary to provide long blades in these lower pressure parts so as to give the necessary area of passage for the steam. i

The object of the present invention is to enable the use of shorter blades in the lower pressure parts without seriously impairing the efiiciency of the turbine.

The invention consists in certain modifications to the cross section combmed with an arrangement of the blades at angles decreasing toward the outlet end of the turbine, whereby the velocity of the steam may in the lower pressure parts, be in a considerably greater ratio to the velocity of the blades than in the higher pressure parts. By thus allowing a greater velocity of steam the height of the low pressure blades may be considcrably lessened and one of the constructional di'l'liculties involved in turbine manufacture may be avoided with practically no loss in eiliciency.

The accompanying diagrams represents copies oi impressions takengof the ends of blades actually tiled.

Figure 1 represents the ordinary arrangement of blades as employed at the high pressure end of the turbine. j ig. Z-reprsents what i callthe semi-wing form in which the angle A of the blade is sli htly less than the angle A of the normal form. Fig. 3 represents what I call my wing form in which the section and angle are still further modified. Fig. 4 shows a still more marked modification which I call the double wing form. The blades in this last case are drop through the blades being the in at a slightly greater pitch than in the form shown in Fig. 3. Fig. 5 is a section. through a turbine provided with blades according to the present invention.

On reference to these diagrams it will be seen that the wing blade is made of section than the type normally employed. the Parsons type of turbines and is very ap proximately bi-laterally symmetrical about the line X Y in Fig. 3. The width of the blade 2 may be 15% to or 30% w' ler in the case of the wing blade than th nary blade shown in Fig. 1. The of the blades represents the angle discharge side. With this shape of hi steam instead oi being brought to tively at the point of impact and momentum again from the drop in as it iiows through the blades in with the ordinary blades-"streams past the blades with high velocity a side thrust upon them on account cat the

slight curvature of the blade, while its veloeit is maintained b r the radual fall in f) f; a

pressure. in Fig. 5 of the accompanying drawings I have shown section through a turbine provided with blades according to this invention. High pressure steam enters the turbine at the end b, and passes through the blades in the direction shown by the ar row 0. Blades included in the dimension line marked (1, are of the nornal form. Those included in'the dimension line marked 6, are of the semi wing form. These in cluded in the line marked f, are of wing form while the blades g, nearest the outlet end h, of the turbine are of the double wing form shown in 4:.

Blades according to this invention 1 win blades because the pressure of earn b a moving at high velocity past their. resembles the action of air upon a birds wings or on an aeroplane. In practice I have found th is possible to pasthree times the vol steam through these wing blades ti sible with blades of normal psangles and of the same weight, the

both cases.

Having now des 'ibed my i I claim as new at i desire c ters Patent isz l 1. In turbines, rows oi sideruble angles to the impinging i bi-laterally l10l17"lil1l1Gl&i :tl near i described.

PIQSSUMB end ef the turbine, m ws ef blecles considerable angles to the impinging fluid at lesser angles to the fluid flow end apand bi-late'relly non-sym'l'nctricel, succes- 1 proximately bi-leterelly symmetrical nee-i eive gi'oups of rows (8, f, and g) at decreasing the low pressure end of the turbine. angles to the impinging fluid and approxi- 2. In turbines, rows of blades near the i mating t0 lei-lateral symmetry, substantially let end, set at considerable angles to the imas described.

pinging fluid and iii-laterally non-symmet- In testimony whereof, I afiix my signature 2o rical, successive rows of blades at diminisl1 in presence of two witnesses.

mg angles to the fluid flow, substantially as CHARLES- ALGERNON PARSONS I u n I l l 3. In it turbine m which steel-m passes I Nltnessesz through rows otlolacles 111 series, rows 01- HENRY GRAHAM DAKYNS, J12, "eledes -118El,1"tl18l1lgl1 pressure end, set at WILLIAM DAGGETT. 

